1. Field of the Invention
This invention relates generally to surgical implantation devices and, more particularly, to surgical implantation devices that are used to repair openings in the walls of body cavities.
2. Description of the Related Art
The present invention can be used in treating an inguinal hernia, for example. Inguinal hernia is a painful condition in which the wall of the abdominal cavity ruptures and a portion of the peritoneum protrudes through the opening in the abdominal wall. The portion of the peritoneum protruding through the abdominal wall must be tied off and pushed back into place and the opening in the wall must be sealed to prevent further injury and infection. These tasks must be accomplished using surgical techniques.
FIG. 1 is a cross-sectional view of a patient with a hernia condition in which the transversalis fascia 12, or abdominal wall, has a ruptured opening 13 with angled edges 14 in the wall defining a frusto-conical circumference. The peritoneum 16 is a membrane that lines the abdominal cavity and acts as a cover for the internal organs, including the intestine (not shown). When the rupture is large enough, typically approximately one centimeter in diameter, the peritoneum and the internal organs behind it can suddenly protrude outwardly past the rupture into the space behind the external oblique muscle 18. This can strain the muscle and press it against the overlaying subcutaneous fat 20 and the skin 22.
One surgical technique commonly used to treat the hernia and seal the rupture is to make an incision in the skin 22 followed by dissection through the subcutaneous fat 20 and external oblique muscle 18 to reach the opening in the transversalis fascia 12. Once exposed, the portion of peritoneum 16 extending through the rupture can be tied off and pushed back to the proper side of the fascia. The opening in the fascia can then be repaired by pulling the opening's angled edges 14 together and keeping them closed by using sutures or surgical staples. This surgical technique can lead to great post-operative discomfort because of the need to cut through many layers of tissue. The large incision requires careful post-operative care to prevent infection from the outside and produces great discomfort while the wound heals. Pulling the opening in the fascia closed also creates a tension on the fascia, which results in additional discomfort. Thus, the incision and the pulling together of the fascia both create difficulties in post-operative recovery.
Another surgical technique commonly used to repair hernias uses a biocompatible prosthetic patch constructed from, for example, polypropylene. The patch is positioned on one side of the fascia, bridging the opening 13. Alternatively, with relatively small openings, the patch is rolled up and inserted lengthwise into the opening, plugging it. In either case, with the passage of time body tissue will grow around and onto the patch and hold it in place. FIG. 2 is a cross-sectional view showing a prosthetic patch 24 placed on top of the fascia 12 covering the opening 13 in accordance with this technique. Unfortunately, the prosthetic patch can move about in relation to the opening before tissue has grown onto it. Such movement produces a less than optimal result and possibly a failure of the seal. In addition, the large incision in the skin 22, with the concomitant discomfort and post-operative difficulties, is still a problem.
More recently, less invasive surgical procedures have been used in conjunction with a laparoscope. A typical laparoscope includes a one-centimeter diameter surgical tube that can be inserted through the patient's skin and through the peritoneum 16 into the peritoneal cavity, toward the center of the abdomen interiorly of the peritoneum. Thus, the surgical tube is approximately of the same diameter as the hernia opening 13 and leaves a relatively small wound. The surgeon views an optical image through the surgical tube and can see the progress of the tube's end as it makes its way in the peritoneal cavity toward the site of the opening. The peritoneum can either be left intact while the tube's end is moved to the opening 13 or the peritoneum can be cut open to extend the tube's end out of the peritoneal cavity to the opening.
At the transversalis fascia opening 13, a prosthetic patch inserted down the length of the surgical tube can be forced out of the tube and moved into its desired position. Post-operative problems are decreased by this procedure because of the smaller external wound left by the surgical tube. The patch, however, still can shift before tissue has grown onto it. The prosthetic patch also can be sutured to the transversalis fascia or peritoneum, to minimize movement. Unfortunately, it can be very difficult to attach the prosthetic patch with sutures using the laparoscope because of difficulties in viewing and in maneuvering through the laparoscope.
From the discussion above, it should be apparent that there is a need for a surgical implantation device and technique for using it that minimize patient discomfort and provide an easier post-operative recovery, that minimize shifting of the device before tissue has grown into place, and that eliminate the need for surgical dissection. The present invention satisfies this need.